Piping system, use of piping system and electric appliance

Abstract

The invention relates to a piping system (1), in particular for cooling an electrical device, preferably for cooling a converter, with at least two, in particular a plurality of piping segments (4, 5, 6), wherein the piping segments (4, 5, 6) are made of PVC, in particular of chlorinated PVC, and wherein the piping segments (4, 5, 6) are joined together by a material bond.

Description

[0001] The present invention relates to a piping system, the use of a piping system and an electrical device with such a piping system.

[0002] Electrical devices that handle high power demands often require a cooling system, which can be liquid cooling. Examples of such devices can be found in high-voltage direct current (HVDC) transmission technology. These might include inverters, which can exhibit significant power losses.

[0003] For the cooling system, which can use water or a water-glycol mixture, state-of-the-art piping systems are employed. These can include straight pipe segments (pipes), pipe bends, branch pieces, and the like. Such a piping system is installed within the electrical device. In addition to simply transporting the fluid, such a piping system must also ensure electrical isolation. Particularly in high-voltage converters, this can result in potential differences of up to 1000 kV.

[0004] In addition, the material from which the piping system is made must be electrically insulating and flame-retardant. The piping system must be able to withstand the pressures and temperatures encountered during operation, which can reach up to 6 bar and 100 °C respectively, for a service life of more than 30 years.

[0005] For this purpose, piping systems made of fluoropolymers are most commonly used. These possess the necessary properties. However, some fluorine compounds are suspected of having negative environmental impacts. For this reason, there are efforts to ban certain fluorine compounds.

[0006] Against this background, the object of the invention is to provide an alternative piping system, in particular for cooling an electrical device, which preferably avoids the aforementioned disadvantages and is environmentally safe.

[0007] This problem is solved by a piping system, in particular for cooling an electrical device, preferably for cooling a converter, with at least two, in particular a plurality of piping segments, wherein the piping segments are made of PVC, in particular of chlorinated PVC (PVC-C), and wherein the piping segments are joined together in a materially bonded manner.

[0008] The invention is based on the fundamental idea of ​​using polyvinyl chloride (PVC) instead of a fluoropolymer as the material for the piping system. Preferably, PVC-C, i.e., chlorinated and / or post-chlorinated polyvinyl chloride, is used. The chlorine content of the PVC-C can be at least 40%, particularly at least 60%, preferably at least 67%, and / or at most 90%, particularly at most 80%, preferably at most 74%. Chlorinated PVC is characterized by good thermal and chemical resistance. Furthermore, chlorinated PVC preferably contains no plasticizer and is therefore also environmentally friendly. In addition, PVC, especially chlorinated PVC, is characterized by good availability and favorable dielectric and insulating properties.

[0009] The PVC, especially chlorinated PVC, may contain stabilizers. In particular, the pipe segments may contain UV stabilizers, which can delay degradation, for example, under the influence of sunlight.

[0010] The piping segments can be or include straight pipe segments, bends, branches, and / or closures. The piping segments can include shut-off devices and / or valves. In other words, a piping system can be composed of a variety of different piping segments. The straight pipe segments can be provided in a suitable length and, for example, connected at their ends to other pipe segments, such as bends, branches, or other straight pipe segments.

[0011] To control the flow rate, particularly of a coolant which may contain or consist of water and / or a water-glycol mixture, shut-off devices and / or valves may be provided. These may be designed in such a way that a free passage cross-section can be varied to adjust the flow rate.

[0012] In a further embodiment, the pipe segments of the piping system according to the invention can be connected to one another by thermal joining connections. In a specific embodiment, these can be welded connections, in particular butt welds. This means that the pipe segments are preferably not bonded to one another, but rather joined together by a thermal joining process, in particular circumferentially. Such an embodiment is characterized in particular by a long service life and reliable leak tightness combined with high mechanical and thermal resistance.

[0013] Specifically, the pipe segments can be joined together by means of butt welding using a heating element and / or infrared welding. In other words, the pipe segments can be joined together by means of butt welding connections using a heating element and / or infrared welding connections, in particular butt welding connections.

[0014] A method for manufacturing the piping system can comprise providing the pipe segments to be joined together and subsequently joining them in a form-fitting manner, in particular by means of a thermal joining process, preferably by means of a welding process, and especially preferably by means of a butt welding process.

[0015] In butt welding with a heating element, a heating element is preferably positioned between the joining surfaces, i.e., between the end faces of the pipe segments to be joined. This heating element heats the two pipe segments in the area of ​​their joining surfaces. After reaching a specific temperature and / or heating time, the heating element is removed from the joining surfaces, and the two pipe segments are pressed together with a defined joining pressure. Preferably, the two pipe segments to be joined remain under the influence of the joining pressure until they have completely cooled down. To produce an infrared weld, the heat in the area of ​​the joining surfaces is introduced by infrared radiation.

[0016] It is also conceivable that the pipe segments are joined using hot gas welding. In this case, the two pipe segments to be joined are heated by a gas flame. Friction welding is also possible in principle, where the pipe segments to be joined are moved relative to each other, with their joining surfaces in contact or being pressed against each other. The relative movement and the associated friction generate heat. As soon as the area around the joining surfaces reaches a certain temperature, the two pipe segments to be joined are pressed together under pressure, creating a metallurgical bond.

[0017] The piping system does not necessarily have to consist solely of PVC pipe segments, particularly chlorinated PVC. Individual sections may also include pipe segments made of other materials. For example, individual sections may contain metallic pipe segments connected to each other and to adjacent PVC pipe segments via suitable connections.

[0018] The piping system may be attached to a support structure or may have fastening means to attach it to a support structure.

[0019] The piping system can also include hose segments. These can serve, for example, as inlet or outlet lines. Hose segments may also be used as expansion joints. The hose segments can contain metallic hoses, such as stainless steel corrugated hoses, and / or plastic hoses, particularly those with metallic reinforcements.

[0020] The problem underlying the invention is further solved by using a piping system, particularly as described above, for cooling an electrical device, especially for cooling an inverter, preferably a FACTS inverter and / or an HVDC inverter. Such inverters may be characterized by high power losses during operation and, consequently, a high cooling requirement. An HVDC inverter is preferably used for high-voltage direct current transmission. In particular, such an inverter can convert three-phase alternating current to direct current and / or direct current to three-phase alternating current as required. A FACTS inverter can be used, in particular, in flexible AC transmission systems.

[0021] Furthermore, the problem underlying the invention is solved by an electrical device, in particular a converter, preferably a FACTS converter and / or an HVDC converter, with a piping system as described above.

[0022] For further details of the invention, reference is made to the dependent claims and to the following description of an exemplary embodiment with reference to the drawing. The drawing shows: Figure 1 A piping system for cooling an electrical device according to the present invention in a schematic perspective view.

[0023] The Figure 1 Figure 1 shows a piping system 1 for cooling an HVDC converter. This is attached to a support structure 2 which has several support profiles 3.

[0024] The piping system 1 comprises a variety of piping segments. These include, for example, straight piping segments 4, pipe bends 5 and branch pieces 6, which can have different nominal diameters.

[0025] The various pipe segments 4, 5, 6 are made of chlorinated PVC and are connected to each other by butt welding connections using heating elements.

[0026] Because the pipe segments are made of PVC-C, i.e., chlorinated PVC, the piping system possesses good chemical and thermal resistance and also has favorable insulating and dielectric properties. At the same time, PVC-C is a cost-effective and widely available material.

[0027] Although the invention has been illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples and other variations can be derived by the person skilled in the art without leaving the scope of protection of the invention.

[0028] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

Claims

1. Piping system (1), in particular for cooling an electrical device, preferably for cooling a converter, comprising at least two, in particular a plurality of piping segments (4, 5, 6), wherein the piping segments (4, 5, 6) are made of PVC, in particular of chlorinated PVC, and wherein the piping segments (4, 5, 6) are joined together in a materially bonded manner.

2. Piping system (1) according to claim 1, characterized by the fact that the pipeline segments are or include straight pipeline segments (4), pipe bends (5), branch pieces (6), closure pieces, and / or that the pipeline segments include shut-off devices and / or valve devices.

3. Piping system (1) according to claim 1 or 2, characterized by the fact that the pipe segments (4, 5, 6) are connected to each other by thermal joining connections.

4. Piping system (1) according to claim 3, characterized by the fact thatthe pipeline segments (4, 5, 6) are connected to each other by welded joints, in particular by butt welds.

5. Piping system (1) according to claim 3 or 4, characterized by the fact that the pipe segments (4, 5, 6) are connected to each other by means of butt welding with heating elements and / or by means of infrared welding.

6. Use of a piping system (1) according to one of claims 1 to 5 for cooling an electrical device, in particular for cooling a converter, preferably for cooling a FACTS converter and / or an HVDC converter.

7. Electrical device, in particular converter, preferably FACTS converter and / or HVDC converter, with a piping system (1) according to one of claims 1 to 6.

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